| ??? 12/21/05 17:24 Read: times |
#105675 - RE: it DOES NOT write to R0 Responding to: ???'s previous message |
I agree with you Jan, IF the register select bits in the PSW were both 0 as everyone expects them to be at program start.
But if they aren't, then the lockup would occur as r0 is then no longer considered to be RAM address 0. All other r0's do get written 0 to them. It's the only explanation I can think of as to why this program would fail. This might be caused by a bootloader of some kind. I would suggest the OP to run a small program which dumps the contents of PSW to one of the ports, where it can be examined if both register select bits are indeed 0 after startup or not: mov p3,psw dead: jmp dead Another way to find out if this is the trouble, the OP could include a line immediately after program_start: mov psw,#0 |
| Topic | Author | Date |
| this code is not working | 01/01/70 00:00 | |
| You solved it! | 01/01/70 00:00 | |
| overreaction | 01/01/70 00:00 | |
| Humility ? | 01/01/70 00:00 | |
| Call it cultural difference... | 01/01/70 00:00 | |
| Sounds familiar | 01/01/70 00:00 | |
| thanks Jan Waclawek | 01/01/70 00:00 | |
| Keil's startup.a51 | 01/01/70 00:00 | |
| hex seems OK | 01/01/70 00:00 | |
| re hex seems OK | 01/01/70 00:00 | |
| And the switch? | 01/01/70 00:00 | |
| and switch | 01/01/70 00:00 | |
| Try a pull-up | 01/01/70 00:00 | |
| switch function | 01/01/70 00:00 | |
| Not at all | 01/01/70 00:00 | |
| reset cap | 01/01/70 00:00 | |
| yeah | 01/01/70 00:00 | |
| It can! | 01/01/70 00:00 | |
| points | 01/01/70 00:00 | |
| Some suggestions | 01/01/70 00:00 | |
| nope | 01/01/70 00:00 | |
| Use LEDs | 01/01/70 00:00 | |
| ok let me follow | 01/01/70 00:00 | |
| That sounds good ! | 01/01/70 00:00 | |
| try this code | 01/01/70 00:00 | |
and what good will that do? | 01/01/70 00:00 | |
| How? | 01/01/70 00:00 | |
| capital | 01/01/70 00:00 | |
| Thanks! | 01/01/70 00:00 | |
| I did the same thing recently | 01/01/70 00:00 | |
| At least... | 01/01/70 00:00 | |
| HORSEFEATHERS | 01/01/70 00:00 | |
| i think yopu didn't got the message | 01/01/70 00:00 | |
| of course it is not | 01/01/70 00:00 | |
| It's easy to fix the code | 01/01/70 00:00 | |
| no, he does not | 01/01/70 00:00 | |
| wrong suggestion | 01/01/70 00:00 | |
| it DOES NOT write to R0 | 01/01/70 00:00 | |
| RE: it DOES NOT write to R0 | 01/01/70 00:00 | |
| why the continued discussion | 01/01/70 00:00 | |
| Time zone | 01/01/70 00:00 | |
| just another guess | 01/01/70 00:00 | |
| She is most likely from India | 01/01/70 00:00 | |
| Irony | 01/01/70 00:00 | |
| Help me | 01/01/70 00:00 | |
| re help me | 01/01/70 00:00 | |
| What happens if? | 01/01/70 00:00 | |
| i will see | 01/01/70 00:00 | |
| "mov @r0,#00h" by "NOP, NOP"? | 01/01/70 00:00 | |
| A good idea | 01/01/70 00:00 | |
| nothing postive | 01/01/70 00:00 | |
| RAM fill ? | 01/01/70 00:00 | |
| re ram fill | 01/01/70 00:00 | |
| Simulator. | 01/01/70 00:00 | |
| Is the CPU really running? | 01/01/70 00:00 | |
| mov p1,r0 | 01/01/70 00:00 | |
| last hope | 01/01/70 00:00 | |
| Tell this first | 01/01/70 00:00 | |
| let me clear | 01/01/70 00:00 | |
| pull ups | 01/01/70 00:00 | |
| re pull ups | 01/01/70 00:00 | |
| a word on pull ups | 01/01/70 00:00 | |
| What to say for that ignorance? | 01/01/70 00:00 |